This application is based on Japanese Patent Application Nos. 2000-112045 filed Apr. 13, 2000 and 2000-395650 filed Dec. 26, 2000, the contents of which are incorporated hereinto by reference.
1. Field of the Invention
The present invention relates to an electric power source device which is installed on a vehicle such that the power source device is cooled with air within the interior space or compartment of the vehicle.
2. Discussion of Related Art
There is known an electric power source device of a comparatively large capacity for an automotive vehicle such as an electric or hybrid vehicle, which power source device is a battery pack fixed on a floor of the vehicle and arranged to be cooled by utilizing air within the vehicle interior space. In this type of electric power source device, there are provided gaps between adjacent ones of a plurality of battery cells of the battery pack so that air introduced from the vehicle interior space flows through the gaps in one direction. An example of the electric power source device of this type for an electric vehicle is disclosed in JP-A-10-252467. In the power source device disclosed in this publication, the battery cells are accommodated within a battery casing which communicates with an air duct open downwards below the rear window of the vehicle, and the air is admitted into the air duct, at a position below the rear window, so that the air introduced into the battery casing through the air duct is circulated through the gaps between the adjacent battery cells, whereby the battery cells are cooled with the air.
In the electric power source device disclosed in the above-identified publication wherein the open end of the air duct for cooling the battery cells is located below the rear window of the vehicle, the length of the air duct and the corresponding distance of flow of the air through the air duct tend to be relatively large, causing a relatively high resistance to a flow of the air through the air duct toward the battery housing, so that the effect of cooling the battery cells tends to be insufficient.
It is therefore an object of the present invention to provide an electric power source device for an automotive vehicle, wherein a resistance to a flow of cooling air to a battery pack is relatively low.
The above object may be achieved according to any one of the following modes or forms of the present invention, each of which is numbered like the appended claims and depends from the other mode or modes, where appropriate, to indicate and clarify possible combinations of elements or technical features. It is to be understood that the present invention is not limited to the technical features or any combinations thereof which will be described for illustrative purpose only. It is to be further understood that a plurality of elements or features included in any one of the following modes of the invention are not necessarily provided all together, and that the invention may be embodied without some of the elements or features described with respect to the same mode.
(1) An electric power source device including a plurality of battery cells accommodated within a battery casing installed on an automotive vehicle, such that the battery cells are cooled by air introduced from a compartment of the vehicle into the battery casing, wherein the battery casing is disposed adjacent to the compartment of the vehicle and is generally isolated from the compartment by a floor which partially defines the compartment, and the floor has an inlet of an air intake passage through which the air is introduced into the battery casing, for cooling the plurality of battery cells.
In the electric power source device constructed according to the above mode (1) of this invention, the battery casing is disposed adjacent to the vehicle compartment and is generally isolated by the floor from the vehicle compartment. The floor has the inlet of the air intake passage through which the air is introduced from the vehicle compartment into the battery casing, to cool the battery cells within the battery casing. This arrangement is effective to shorten the required length of the air intake passage between the inlet and the battery casing, permitting significant reduction of a resistance to a flow of the cooling air through the air intake passage, and thereby assuring an accordingly increased effect of cooling of the battery cells. electric power source device is available at an accordingly reduced cost.
(3) An electric power source device including a plurality of battery cells accommodated within a battery casing installed on an automotive vehicle, such that the battery cells are cooled by air introduced from a compartment of the vehicle into the battery casing through an intake air passage, wherein the battery casing is accommodated within an interior space whose upper wall is defined by a floor of the vehicle, and the upper wall has an inlet of an air intake passage through which the air is introduced into the battery casing.
In the electric power source device constructed according to the above mode (3) of this invention, the battery casing is disposed adjacent to the vehicle compartment and is generally isoalted by the vehicle floor from the vehicle compartment. Namely, the battery casing is accommodated within the interior space whose upper wall is defined by a portion of the vehicle floor. The upper wall space has the inlet of the air intake passage through which the air is introduced from the vehicle compartment into the battery casing, to cool the battery cells within the battery casing. This arrangement is effective to shorten the required length of the air intake passage between the inlet and the battery casing, permitting significant reduction of a resistance to a flow of the cooling air through the air intake passage, and thereby assuring an accordingly increased effect of cooling of the battery cells. Further, the required lengths of components which define the air intake passage, for instance, the
(2) An electric power source device including a plurality of battery cells accommodated within a battery casing installed on an automotive vehicle, such that the battery cells are cooled by air introduced from a compartment of the vehicle into the battery casing through an intake air passage, wherein the battery casing is disposed adjacent to the compartment of the vehicle and is generally isolated from the compartment by a covering member which is disposed within a body shell of the vehicle so as to cover the battery casing, and the covering member has an inlet of the air intake passage, through which the air is introduced into the battery casing.
In the electric power source device constructed according to the above mode (2) of this invention, the battery casing is disposed adjacent to the vehicle compartment and is generally isolated by the covering member from the vehicle compartment. The covering member has the inlet of the air intake passage through which the air is introduced from the vehicle compartment into the battery casing, to cool the battery cells within the battery casing. This arrangement is effective to shorten the required length of the air intake passage between the inlet and the battery casing, permitting significant reduction of a resistance to a flow of the cooling air through the air intake passage, and thereby assuring an accordingly increased effect of cooling of the battery cells. Further, the required lengths of components which define the air intake passage, for instance, the required length of an air intake duct, can be reduced, so that the components are available at accordingly reduced costs, and the required length of an air intake duct, can be reduced, so that the components are available at accordingly reduced costs, and the electric power source device is available at an accordingly reduced cost.
(4) An electric power source device according to any one of the above modes (1)-(3), wherein the inlet is provided under a seat disposed in the compartment of the vehicle.
According to the above mode (4) of the invention, the inlet of the air intake passage is generally covered by the seat, so that a noise due to the flow of the air through the air intake passage is less likely to be heard within the vehicle compartment.
(5) An electric power source device according to any one of the above modes (1)-(4), wherein the air intake passage is a generally curved passage including a first straight segment extending substantially downwards from the inlet, a second straight segment extending substantially horizontally, and a curved segment which extends between the first and second straight segments, the generally curved passage being partially defined by a curved shielding plate which is fixed at a position on an inner side of a curve of the generally curved passage.
In the electric power source device according to the above mode (5), the air is introduced from the vehicle compartment into the battery casing through the generally curved air intake passage, which is partially defined by the curved shielding plate. This arrangement prevents entry of foreign matters from the vehicle compartment into the battery casing, even if the foreign matters are introduced together with the air into the first straight segment of the passage, which first segment extends substantially downwards from the inlet of the passage. That is, the curved segment of the curved air intake passage partially defined by the curved shielding plate does not permit a movement of the foreign matters into the second straight portion extending substantially horizontally toward the battery casing located downstream of the shielding plate. The foreign matters may include liquid substances spilt within the vehicle compartment. Further, the shielding plate prevents passengers within the vehicle compartment from seeing the battery casing through the air intake passage. In other words, the shielding plate conveniently hides the battery casing, which would deteriorate the appearance of the interior of the vehicle.
(6) An electric power source device according to any one of the above modes (1)-(5) further including a blower fan which constitutes a part of the air intake passage and which is operable to blow the air into the battery casing, and a shielding plate which partially defines said air intake passage such that said air intake passage is generally curved, so as to prevent a flow of the air from the inlet of the air intake passage directly into an inlet of the blower fan.
In the electric power source device according to the above mode (6), the air introduced from the vehicle compartment into the air intake passage is blown into the battery casing by the blower fan, and the shielding plate is provided to partially define the air intake passage such that the air intake passage is generally curved so as to prevent the air flow directly into the battery casing. This arrangement prevents entry of foreign matters from the vehicle compartment into the blower fan, even if the foreign matters are introduced together with the air into the generally curved air intake passage. That is, the shielding plate which defines the generally curved air intake passage does not permit a movement of the foreign matters into the battery casing located downstream of the shielding plate. The foreign matters may include liquid substances spilt within the vehicle compartment. Further, the shielding plate prevents passengers within the vehicle compartment from seeing the blower fan through the air intake passage. In other words, the shielding plate conveniently hides the blower fan, which would deteriorate the appearance of the interior of the vehicle. In addition, the shielding plate prevents propagation of the operating noise of the blower fan into the vehicle compartment, thereby reducing the discomfort of the vehicle passengers due to the operating noise.
(7) An electric power source device according to the above mode (5) or (6), wherein the shielding plate includes a distal end portion which is turned on an inner side of a curve of the air intake passage, the inlet of the air intake passage being located on an outer side of the curve.
The shielding plate in the above mode (7) is effective to reduce the frictional resistance of its distal end portion to the air flow, and accordingly reduce the deceleration of the air stream at the distal end portion, permitting an increased effect of cooling of the battery cells.
(8) An electric power source device including a battery module disposed under a seat of an automotive vehicle, such that said battery module is cooled by air introduced through an air intake passage, the battery module consisting of a plurality of battery cells superposed on each other in a stack, wherein the seat has a lower surface defining an under-seat space which is held in communication with a compartment of the vehicle, and the air intake passage has an inlet which is held in communication with the under-seat space, so that the air for cooling the battery module is introduced from the compartment into the air intake passage through the under-seat space and the inlet.
In the electric power source device constructed according to the above mode (8) of this invention, the inlet of the air intake passage is held in communication with the under-seat space which is partially defined by the lower surface of the vehicle seat and which is held in communication with the vehicle compartment, so that the air for cooling the battery module is introduced into the air intake passage through the under-seat space and the inlet. According to this arrangement, the required length of the air intake passage for introducing the air for cooling the battery module disposed under the vehicle seat can be significantly reduced, so that the resistance to the air flow through the air intake passage can be accordingly reduced. Further, the inlet of the air intake passage and the under-seat space in communication with that inlet are almost covered by the vehicle seat. This arrangement utilizes an otherwise dead space under the vehicle seat, and permits reduction of the noise of the air flow as heard within the vehicle compartment, as compared with an arrangement in which the inlet of the air intake passage is formed through a front wall of a structure on which the seat is mounted and in which the battery module is accommodated.
(9) An electric power source device including a battery module accommodated within an interior space partially defined by an under-seat covering panel on which a seat of an automotive vehicle is mounted, the battery module being cooled by air introduced through an air intake passage, the battery module consisting of a plurality of battery cells superposed on each other in a stack, wherein the under-seat covering panel cooperates with a lower surface of the seat to define therebetween an under-seat space which extends in a lateral direction of the vehicle and which has an opening in the form of a generally elongate slot, the under-seat space communicating through the opening with a portion of a compartment of the vehicle which portion is located in front of the seat, and the air intake passage has an inlet in communication with the under-seat space.
In the electric power source device constructed according to the above mode (9) of this invention, the under-seat space is defined between the under-seat covering panel and the lower surface of the vehicle seat. This under-seat space has the opening in the form of a generally elongate slot through which the under-seat space is held in communication with the vehicle compartment and the inlet of the air intake passage. In this arrangement, the air is introduced from the vehicle compartment into the inlet of the air intake passage through the under-seat space. According to this arrangement, the required length of the air intake passage for introducing the air for cooling the battery module disposed under the vehicle seat can be significantly reduced, and the resistance to the air flow through the intake air passage can be accordingly reduced. Further, the under-seat space in communication with the vehicle compartment is almost covered by the vehicle seat. This arrangement utilizes an otherwise dead space under the vehicle seat, and permits reduction of the noise of the air flow as heard within the vehicle compartment, as compared with an arrangement in which the inlet of the air intake passage is formed through a front wall of the under-seat covering panel, which front wall is located right below the front end of the vehicle seat.
(10) An electric power source device according to the above mode (8) or (9), wherein the battery cells of the battery module are superposed on each other in a direction of each battery cell so as to form an elongate stack, such that gaps are formed between adjacent ones of the battery cells, so as to extend in one direction perpendicular to a longitudinal direction of said elongate stack, and the seat of the vehicle is a bench disposed so as to extend in a lateral direction of the vehicle. In this case, the battery module is disposed under the bench such that the longitudinal direction of the elongate stack is parallel to the lateral direction of the vehicle. In the present arrangement, the air introduced through the air intake passage is fed to flow through the gaps between the adjacent battery cells in the predetermined direction, so that the battery cells superposed on each other in their thickness direction can be effectively cooled by the air flowing through the gaps, and the service life of the battery cells can be prolonged.
(11) An electric power source device according to the above mode (10), wherein the battery module is accommodated within a battery casing such that the battery casing and the battery module cooperate to define an air intake chamber and an air exhaust chamber on opposite sides of said battery module, such that the air intake chamber communicates with the air intake passage, while the air exhaust chamber communicates with an air exhaust passage provided with a blower fan. When blower fan is operated, the air is drawn from the air intake passage into the air exhaust passage through the air intake chamber, the above-indicated gaps between the battery cells, and the air exhaust chamber, which are formed within the battery casing. Thus, the battery module is effectively cooled, and the service life of the battery module is prolonged.
(12) An electric power source device according to the above mode (10), wherein the battery module is accommodated within a battery casing such that the battery casing and the battery module cooperate to define an air intake chamber and an air exhaust chamber on opposite sides of said battery module, such that the air intake chamber communicates with the air intake passage provided with a blower fan, while the air exhaust chamber communicates with an air exhaust passage. When blower fan is operated, the air introduced into the air intake passage is forced to flow through the air intake chamber, the above-indicated gaps between the battery cells, and the air exhaust chamber, which are formed within the battery casing. Thus, the battery module is effectively cooled, and the service life of the battery module is prolonged. In this arrangement wherein the blower fan 31 connected to the air intake passage is operated to blow the air into the air intake chamber through the air intake passage, the pressure in the air intake chamber tends to be higher than the atmospheric pressure outside the battery casing, so that the comparatively hot air outside the battery casing is prevented from entering the battery casing. The entry of the hot air into the battery casing would cause an undesirable temperature gradient in the direction of thickness of the battery cells, which may cause a variation in the properties of the battery cells due to the temperature gradient. The present arrangement is effective to reduce the above-indicated temperature gradient and property variation of the battery cell.
(13) An electric power source device according to the above mode (11) or (12), wherein said air exhaust passage is held in communication with an exterior space of the vehicle. According to this arrangement, the air whose temperature has been raised after as a result of its flow through the gaps between the battery cells is discharged into the exterior of the vehicle, so that the temperature rise of the air in a space in which the battery casing is accommodated can be effectively reduced.